The study found that for women with “triple-negative” breast cancer, adding Keytruda to standard chemotherapy improved their odds of responding.
And in the months afterward, women treated with the drug were less likely to see their cancer come back.
The findings are encouraging in a disease that is challenging to treat, said Dr. Skip Burris, president of the American Society of Clinical Oncology.
“I think these results will be greeted enthusiastically by doctors and patients,” said Burris, who was not involved in the trial.
Triple-negative breast cancers account for about 10% to 15% of all breast cancers, according to the American Cancer Society. They are so called because the cancer‘s growth is not fueled by estrogen, progesterone or a protein called HER-2.
Unfortunately, Burris said, that means women with the disease are unlikely to benefit from the hormone therapies and “targeted” drugs that have greatly improved breast cancer survival for U.S. women.
Instead, the mainstays of treatment are surgery and chemotherapy.